Process of preserving wood.



nomical treatment.

v UNITED STATES PAT ENT OFFICE. OABLE'I'ON ELLIS, o'r momcmm, New JERSEY, assrenon r0 corran orurnonucrs COMPANY, A coaroaarrou, or NEW 201m,

PROCESS OF PRESER-VING WOOD.

No Drawing.

Specification of Letters Patent.

Patented Feb. 13, 1912.

Application filed June 14, 1911. Serial No. 633,076.

State of New Jersey, have invented certain new and useful Improvements in Preserved lVood and Processes of Making Same, of which the following is a specification.

This invention relates to a preserved wood product and the process of making same and relates in particular to railroad tles preserved with oil-soluble ELISGIllC compounds. I v

The methods heretofore employed for preserving wood have had todo particularly with the injection into wood of. aqueous solutions of copper sulfate, zinc chlorid and mercury chloride, or of such organic preservatives as creosote and coal tar or water proofing agents such as petroleum products, of which Bakersfield oil is typical.

Aqueous solutions of the water-soluble preservative salts are open to the objection that when the-wood is exposed to dampness the salts are leached out, more orless, reducing the preservative action correspond- Creosote oils while fairly effective, are not easily obtainabledn the large quantities required at a cost which will permit of eco- Crude petroleum, and more particularly its light-distillate-free residues, have desir-' able water-proofing qualities, being superior in this respect to creosote. Moreover these heavy oils or residues have 'a much higher flash point than creosote, as a rule, so that the fire risk in treating wood with heavy petroleum is very slight in comparison with creosote. In the treatment of wood which is to be subjected to great mechanical stress, railroad ties for example, a-preferred feature of my invent-ion is the application and use of a preservative whose specific preservative action is carefully regulated to endure for a period substantially that of the mechanical life of the ties. Creosote may be and is used in such proportion that ties show no signs of decay even after their mechanicalefliciency is lost. Ordinary petroleum To be sure there are oils although having a desirable water-- proofing action (which by the way is especially pronounced in asphaltic oil residues) have not suflicient fungus-resisting properties to preserve railroad ties up to; the extent of their mechanical life. In fact, in the treatment of ties with western Bakersfield crude oil, or-Mexican Ebano asphaltic I oil for example, it has been the practice to saturate or completely impregnate the tie with a relatively large quantity of the pe-' troleum oil, which perhaps is not-particularly costly if done locally, that is near the source of oil supply, but which would be expensive if the impregnating and saturating processes were carried out at a long distance from the oil regions. The practice in creosoting ties is to inject simply the amount of creosote which will wet the fibers as it were, without filling the pores of the wood with the creosote (empty cell process) Therefore in comparing the-cost of creosoting treatment with petroleum oil treatment cognizance must be taken of the relatively large amount of petroleum oil apparently necessarily employed. v

In the present invention it is especially the object to fortify petroleum oil such as petroleum residues and heavy distillates, in particular those derived from asphaltic oil, with an antiseptic and preservative compound which has the bactericidalproperties.

of creosote, for example, and the fungicidal properties which creosote lacks, and to produce an oil which when introduced into wood in relatively small quantity will preserve it against moisture and decay with out the necessity of resorting to full cell treatment; 1

.Thepresent invention also contemplates the process of treating railroad ties and other woody or fibrous material to form the aforesaid preserved wood product; that is to say, the process which consists or in volves dissolving in an oil, such as petroleum oil and particularly that form known as asphaltic oil, a relatively small quantity of a high powered antiseptic, more particularly' the oil-soluble derivatives of arsenic and copper or mixtures of these, and in fibercoating the tie or other wood to a more or less extent, adjusting the' amount of oil to this end and proportioning the amount life" of the tie.

whereby the preservative life or action and mechanical life substantially coincide.

In carrying out my invention I may combine arsenic (or mercury etc.) with an oilsoluble base or a radical, so as to render it soluble in ordinary vpetroleum oils and I treat wood, as for example railroad ties, with this oil under conditions which preferably produce merely a fiber coating of the oil in the interior of the wood (empty cell) in contradistinction to the present practice of impregnating wood with a saturating amount (full cell) of Bakersfield or other petroleum oil. In this manner the advantages of petroleum (asphaltic) oil as an inexpensive water-resisting material are secured so that a preserved wood product is obtained which carries apredetermined or adjusted amount of arsenic or similar powerful preservative such as mercury, whereby the preservative efl'ect of the oil is made practically coincident with the mechanical This secures marked advantages as regards the cost of treatment as will be evident.

In carrying out my invention I preferably make use of a compound of arsenic with an oily base, which compound is introduced in small quantity into the cheap petroleum oil diluent and waterproofing agent. Semi-drying oils such as corn or cotton seed oil, soya bean, rosin oil and the' like or drying oils such as linseed and Chinese wood oil, are treated with an arsenic compound capable of combination therewith. Chlorid of arsenic is suitable for this purpose. This compound is an acid body and the resulting oil-arsenic compound therefore has an acid reaction. By washing with wateror water rendered slightly alkaline with carbonate of soda or hydrate of lime the acidity may be removed and the neutral and nearly neutral arsenated oily base may then be: dissolved in heavy petroleum-oil such, as asphaltic oilresidues. The latter oil should be chosen with respect to its impregnating qualities as too viscous an oil would not enter the wood readily except under a very high temperature and pressure. 'On the other hand as heavyagrade of asphaltic oil should'be selected as is consistent with ease of impregnation, suitable oils being cheaply obtainable as indicated. A very heavy bodied asphalt oil may be rendered workable by the' addition of 25% or so of spindle oil or creosote. From 1% to 5% of the arsenated oily base is introduced into the asphaltic oil, heat being employed for incorporating when necessary especially when adding the arsenic compound to a heavy bodied viscous product. Arsenic chlorid combines easily with unsaturated organic compounds olefines, terpenes etc. and those which have high molecular weight especially tend to form oil-soluble molecular comthis mixture introduced into the wood preferably so as to give merely a fiber-coating, adjusting the amount of the high-powered preservative with reference to the total amount of oil injected into the wood so that the duration of preservative action substantially corresponds to the mechanical life of the tie or other treated wood. It is well known that different woods vary in endurance to mechanical stress; a white oak railroad tie has a longer mechanical life than a red oak tie. Variations in the mechanical life of ties are still more marked in the case ,of cypress, eucalyptus and lob-lolly. In each case, the mechanical life being determined, it is suflicientto'treat the tie with substantially a fiber coating quantity of the petroleum oil, carrying the high-powered preservative sufficient inamount to carry the preserving action through a period of years,

equal to or approximating the mechanical life of the tie. oak tie asphaltic oil having a gravity of about .93 is treated with 3% of copper ricijnoleate and 3%; lbs. of the oil per cubic foot pine an ,of tie are injected. With lob-lolly asphaltic oil of .965 specific gravity is treat 'ed with 4% of arsenated cotton-seed oil and 45- pounds of the oil per cubic foot of tie are injected. j

The actual injecting procedure employed in carrying out the process and producing the product of the present invention may be any of the standard methods'nowemployed for that purpose, as for example, the ties first may be subjected to a very considerable air pressure, '(say 75 lbs.) then treated with the oil at say 130 F. under a higher pressure (say '85 lbs.) and the pressure gradually increased to say 225 lbs. until suf-v ficient penetration is secured. The pressure may then be released whereupon the confined air within the tie expands forcing the excess of arseniated or other oil out of the pores, leaving only a fiber-coating of the preservative.

To recapitulate: )Ihe present invention relates to the process ofv preserving wood, particularly railway ties, comprising injecting into the tissues of the material, a fiber-coat- For example with a white ing amount of an oil, preferably of a pctroleum asphalt nature, containing a. highpowered preservative, miscible therewith, or in solution therein, such high powered preservative preferably being an oil-soluble arsenical, in preferably coating the entire or lar to preserved wood containing the arseni- I ated oil, substantially as described. 20 I Tl'llS application is in part a divisional continuation of my co-pending application Serial No, 474,565; that is to say that the present application contains matter derived from aforesaid application but does not claim broadly the use of asphalt oils containing a metallo-organic antiseptic or other high-powered preservative.

What I claim is: 4

1. 'lhe herein described process of preserving railroad ties and other fibrous material, which consists in injecting into said ties and the like, at least amount of an oil comprising asphaltic petroleum carrying arsenic material in solution therein, the said arsenic material being present in predetermined amount whereby preservative action persists for a stantially equivalent to that of the mechani= period subcal life of the tie and similar material and preferably in proa fiber-coating I Witnesses in causing the major portion of the interior fiber of said ties and similar material to .be substantially uniformly coated with said oil.

2. The herein described process of preserving railroad ties and other fibrous material which consists in injecting thereinto at least a fiber-coating amount of an oil comprising asphaltic petroleum carrying antiseptic material in solution in the oil, the said antiseptic material being present in predetermined amount whereby preservative action substantially coincides with the mechanical life of the fibrous structure, and in causing the major portion of the interior fibers of said structure to be coated with said oil.

3. A preserved wood product comprising wood containing oil-soluble arsenic in solution in a petroleum oil.

4. A preserved wood product comprising wood containing a solution of an arsenic compound in an oil.

5. A- preserved woodproduct comprising wood having its interior fibers coated with a solution of an arsenic compound in an oil 5. A preserved wood product consisting of a-railroad tie having its interior fibers coated with asoluti'on asphaltic oil. Y T

Signed at Montclair in the county of Essex and State of New Jersey this 13th day of June A. D. 1911-.

CARLETON ELLIS.

of an arsenic compound in NATHANIEL L. FOSTER, BIRDELLA M. ELLIs. 

